MM-25006: Fix occurences of unclosed http bodies (#14521)

* MM-25006: Fix occurences of unclosed http bodies

And while here, we also use ioutil.Discard to read the remaining
body instead of reading with ioutil.ReadAll which allocates a separate
byte buffer.

* Fix mistake

* Address review comments

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

services/marketplace/client.go

@@ -5,6 +5,7 @@ package marketplace
 
 import (
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -79,7 +80,7 @@ func (c *Client) GetPlugin(filter *model.MarketplacePluginFilter, pluginVersion
 // closeBody ensures the Body of an http.Response is properly closed.
 func closeBody(r *http.Response) {
 	if r.Body != nil {
-		_, _ = ioutil.ReadAll(r.Body)
+		_, _ = io.Copy(ioutil.Discard, r.Body)
 		_ = r.Body.Close()
 	}
 }